FFRacing79

The TPS is just that...a sensor. All it does is send an input to the ignition, just as an engine temp sensor or baro sensor would.
On some model YZs, unplugging it resulted in a better running motor.
Think of it this way...no info(unplugged) is better than wrong info(improperly adjusted).

DoctorRzed

FFRacing79

Throttle Position Sensor...
If your ignition had no TPS, it would operate with what is called a 1-D(dimensional) map. That means the only thing controlling the ignition requirements is RPM. It would use a preset signal at a given RPM.
With the TPS connected and adjusted properly, your ignition has a 2-D map, using rpm and tps inputs to determine a predetermined signal.
The more inputs(sensors)your ignition has available to it, the more accurately it can determine the proper ignition curve to use. This is why fuel injection will be a big boost to these motors when it becomes available. Instead of trying to tune the motor with 4 carb circuits, you will be able to program the EFI to react to almost any given situation much more precisely with fuel and ignition.
The reason I found that disconnecting the TPS a benefit on some of the 450s was I believe there was a "glitch" in the 2-D map and that with the TPS input, it actually lost power in certain areas.
Hope I wasnt to confusing here, as I tried to make it as simple and accurate as I know how.

anyway, by tricking the TPS, you can fool the ignition into retard or advance, you could use this advantage to increase torque a bit in the dead zone with a finger button I suppose. We are just happy it is there.for 10 bucks you can make the perfect timing retard unit instead of spending hundreds of dollars on a system .

revolucien

A lot of people like disconnecting it because it supposedly softens some of the engines hit. I tried disconnecting the TPS wires and didn't like it. I would rather control the hit myself than not have it available.